Waikato District Health Board leaders do not hide from their hospitals' unenviable status as having one of the highest death rates in the country.

In each of the five years to June last year, Waikato was among the three highest DHBs on standardised Health Ministry statistics.

And in three of those years, including 2010/11, it was highest.

But Waikato's in-hospital standardised mortality rate is coming down, in line with the national trend. In 2010/11, 775 inpatients died.

That was a standardised rate of 1.78 per cent of all inpatients - compared with 1.48 per cent for all DHBs - after statistical weightings by the Health Ministry to account for local differences in population, disease and injury characteristics.

In July, Waikato and other DHBs refused to give the Herald the hospital mortality rate reports done for them by the Health Roundtable, partly because the data can contain inaccuracies.

Yesterday, Waikato released its January-June 2012 Roundtable rate and indicated it should be preferred over the much-higher 2010/11 figure from the ministry, even though different agencies can count mortality rates differently.

"Mortality as well as safety, we take it very seriously," said Waikato DHB chief operating officer Jan Adams. "We have got a complete focus on quality. It's our number one priority.

"We have inpatient palliative care, which skews our data. Notwithstanding, we know our figures are at the higher-range end and we want to know what and why, which is why we have set up the mortality review process for every death."

A DHB clinical leader, Dr Phil Wood, said, "We have ... one of the most comprehensive mortality review processes I have come across, and we are all too aware of a number of important reviews of our clinical activity.

"We are not afraid of comparing ourselves with other Australasian hospitals and using this data to inform us of where to push for improvement."

Dr Wood said living far from hospital contributed to avoidable deaths. Efforts were being made to address this with better community services and better support in transit.

Waikato was the first DHB - last year - to publish an annual quality report, listing the progress of its patient safety and quality-care projects. The national Health Quality and Safety Commission wants all health providers to follow suit by next June.

The 2011/12 Waikato quality report shows the trend line on avoidable deaths was down markedly, to around 7 per cent of all hospital deaths by June, from 17 per cent in July lastyear.

Medication errors declined from more than 3.5 per 100 patient admissions, to just over 2.5.

The Bay of Plenty DHB is another that usually has a higher hospital mortality rate, ranging from eighth to second-highest in the five years to June last year. In 2010/11, it had 430 inpatient deaths.

Chief operating officer Phillip Balmer said the board knew it was in the upper range and had begun safety and quality schemes to address the issue. They had helped reduce the mortality rate and were expected to bring further reductions.

These included standardising handover information to lower the risks - frequently identified in medical error reports - associated with the transfer of patients between clinicians.

Bay of Plenty had, like all DHBs, striven to reduce rates of hospital-acquired infections. It had been free of infections associated with central lines inserted into patients' veins for more than two years.

The series

Five years of hospital death rates have been made public for the first time - in the Herald. We compare health boards, investigate where lives are being lost and the battle to save them.

This week

Monday - District health boards compared, is death rate linked to healthcare quality, and how a simple checklist helps surgeons to avoid mistakes.Yesterday - Waitemata DHB boosts heart-care capacity. A bereaved father questions medical justice.Today - Waikato DHB strives to understand its high death rate, medication safety, and a doctor's apology.Tomorrow - Palliative care helps Auckland DHB's good performance. A widow fights for changes.Friday - Obesity skews the statistics in South Auckland. Lives saved by reduction of blood infections.